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<span id="Integer-library-routines"></span><div class="header">
<p>
Next: <a href="Soft-float-library-routines.html" accesskey="n" rel="next">Soft float library routines</a>, Up: <a href="Libgcc.html" accesskey="u" rel="up">Libgcc</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html" title="Index" rel="index">Index</a>]</p>
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<hr>
<span id="Routines-for-integer-arithmetic"></span><h3 class="section">4.1 Routines for integer arithmetic</h3>

<p>The integer arithmetic routines are used on platforms that don&rsquo;t provide
hardware support for arithmetic operations on some modes.
</p>
<span id="Arithmetic-functions"></span><h4 class="subsection">4.1.1 Arithmetic functions</h4>

<dl>
<dt id="index-_005f_005fashlsi3">Runtime Function: <em>int</em> <strong>__ashlsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fashldi3">Runtime Function: <em>long</em> <strong>__ashldi3</strong> <em>(long <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fashlti3">Runtime Function: <em>long long</em> <strong>__ashlti3</strong> <em>(long long <var>a</var>, int <var>b</var>)</em></dt>
<dd><p>These functions return the result of shifting <var>a</var> left by <var>b</var> bits.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fashrsi3">Runtime Function: <em>int</em> <strong>__ashrsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fashrdi3">Runtime Function: <em>long</em> <strong>__ashrdi3</strong> <em>(long <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fashrti3">Runtime Function: <em>long long</em> <strong>__ashrti3</strong> <em>(long long <var>a</var>, int <var>b</var>)</em></dt>
<dd><p>These functions return the result of arithmetically shifting <var>a</var> right
by <var>b</var> bits.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fdivsi3">Runtime Function: <em>int</em> <strong>__divsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fdivdi3">Runtime Function: <em>long</em> <strong>__divdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dt id="index-_005f_005fdivti3">Runtime Function: <em>long long</em> <strong>__divti3</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>
<dd><p>These functions return the quotient of the signed division of <var>a</var> and
<var>b</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005flshrsi3">Runtime Function: <em>int</em> <strong>__lshrsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005flshrdi3">Runtime Function: <em>long</em> <strong>__lshrdi3</strong> <em>(long <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005flshrti3">Runtime Function: <em>long long</em> <strong>__lshrti3</strong> <em>(long long <var>a</var>, int <var>b</var>)</em></dt>
<dd><p>These functions return the result of logically shifting <var>a</var> right by
<var>b</var> bits.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fmodsi3">Runtime Function: <em>int</em> <strong>__modsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fmoddi3">Runtime Function: <em>long</em> <strong>__moddi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dt id="index-_005f_005fmodti3">Runtime Function: <em>long long</em> <strong>__modti3</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>
<dd><p>These functions return the remainder of the signed division of <var>a</var>
and <var>b</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fmulsi3">Runtime Function: <em>int</em> <strong>__mulsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fmuldi3">Runtime Function: <em>long</em> <strong>__muldi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dt id="index-_005f_005fmulti3">Runtime Function: <em>long long</em> <strong>__multi3</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>
<dd><p>These functions return the product of <var>a</var> and <var>b</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fnegdi2">Runtime Function: <em>long</em> <strong>__negdi2</strong> <em>(long <var>a</var>)</em></dt>
<dt id="index-_005f_005fnegti2">Runtime Function: <em>long long</em> <strong>__negti2</strong> <em>(long long <var>a</var>)</em></dt>
<dd><p>These functions return the negation of <var>a</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fudivsi3">Runtime Function: <em>unsigned int</em> <strong>__udivsi3</strong> <em>(unsigned int <var>a</var>, unsigned int <var>b</var>)</em></dt>
<dt id="index-_005f_005fudivdi3">Runtime Function: <em>unsigned long</em> <strong>__udivdi3</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>)</em></dt>
<dt id="index-_005f_005fudivti3">Runtime Function: <em>unsigned long long</em> <strong>__udivti3</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>)</em></dt>
<dd><p>These functions return the quotient of the unsigned division of <var>a</var>
and <var>b</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fudivmoddi4">Runtime Function: <em>unsigned long</em> <strong>__udivmoddi4</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>, unsigned long *<var>c</var>)</em></dt>
<dt id="index-_005f_005fudivmodti4">Runtime Function: <em>unsigned long long</em> <strong>__udivmodti4</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>, unsigned long long *<var>c</var>)</em></dt>
<dd><p>These functions calculate both the quotient and remainder of the unsigned
division of <var>a</var> and <var>b</var>.  The return value is the quotient, and
the remainder is placed in variable pointed to by <var>c</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fumodsi3">Runtime Function: <em>unsigned int</em> <strong>__umodsi3</strong> <em>(unsigned int <var>a</var>, unsigned int <var>b</var>)</em></dt>
<dt id="index-_005f_005fumoddi3">Runtime Function: <em>unsigned long</em> <strong>__umoddi3</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>)</em></dt>
<dt id="index-_005f_005fumodti3">Runtime Function: <em>unsigned long long</em> <strong>__umodti3</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>)</em></dt>
<dd><p>These functions return the remainder of the unsigned division of <var>a</var>
and <var>b</var>.
</p></dd></dl>

<span id="Comparison-functions"></span><h4 class="subsection">4.1.2 Comparison functions</h4>

<p>The following functions implement integral comparisons.  These functions
implement a low-level compare, upon which the higher level comparison
operators (such as less than and greater than or equal to) can be
constructed.  The returned values lie in the range zero to two, to allow
the high-level operators to be implemented by testing the returned
result using either signed or unsigned comparison.
</p>
<dl>
<dt id="index-_005f_005fcmpdi2">Runtime Function: <em>int</em> <strong>__cmpdi2</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dt id="index-_005f_005fcmpti2">Runtime Function: <em>int</em> <strong>__cmpti2</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>
<dd><p>These functions perform a signed comparison of <var>a</var> and <var>b</var>.  If
<var>a</var> is less than <var>b</var>, they return 0; if <var>a</var> is greater than
<var>b</var>, they return 2; and if <var>a</var> and <var>b</var> are equal they return 1.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fucmpdi2">Runtime Function: <em>int</em> <strong>__ucmpdi2</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>)</em></dt>
<dt id="index-_005f_005fucmpti2">Runtime Function: <em>int</em> <strong>__ucmpti2</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>)</em></dt>
<dd><p>These functions perform an unsigned comparison of <var>a</var> and <var>b</var>.
If <var>a</var> is less than <var>b</var>, they return 0; if <var>a</var> is greater than
<var>b</var>, they return 2; and if <var>a</var> and <var>b</var> are equal they return 1.
</p></dd></dl>

<span id="Trapping-arithmetic-functions"></span><h4 class="subsection">4.1.3 Trapping arithmetic functions</h4>

<p>The following functions implement trapping arithmetic.  These functions
call the libc function <code>abort</code> upon signed arithmetic overflow.
</p>
<dl>
<dt id="index-_005f_005fabsvsi2">Runtime Function: <em>int</em> <strong>__absvsi2</strong> <em>(int <var>a</var>)</em></dt>
<dt id="index-_005f_005fabsvdi2">Runtime Function: <em>long</em> <strong>__absvdi2</strong> <em>(long <var>a</var>)</em></dt>
<dd><p>These functions return the absolute value of <var>a</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005faddvsi3">Runtime Function: <em>int</em> <strong>__addvsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005faddvdi3">Runtime Function: <em>long</em> <strong>__addvdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dd><p>These functions return the sum of <var>a</var> and <var>b</var>; that is
<code><var>a</var> + <var>b</var></code>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fmulvsi3">Runtime Function: <em>int</em> <strong>__mulvsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fmulvdi3">Runtime Function: <em>long</em> <strong>__mulvdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dd><p>The functions return the product of <var>a</var> and <var>b</var>; that is
<code><var>a</var> * <var>b</var></code>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fnegvsi2">Runtime Function: <em>int</em> <strong>__negvsi2</strong> <em>(int <var>a</var>)</em></dt>
<dt id="index-_005f_005fnegvdi2">Runtime Function: <em>long</em> <strong>__negvdi2</strong> <em>(long <var>a</var>)</em></dt>
<dd><p>These functions return the negation of <var>a</var>; that is <code>-<var>a</var></code>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fsubvsi3">Runtime Function: <em>int</em> <strong>__subvsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>
<dt id="index-_005f_005fsubvdi3">Runtime Function: <em>long</em> <strong>__subvdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>
<dd><p>These functions return the difference between <var>b</var> and <var>a</var>;
that is <code><var>a</var> - <var>b</var></code>.
</p></dd></dl>

<span id="Bit-operations"></span><h4 class="subsection">4.1.4 Bit operations</h4>

<dl>
<dt id="index-_005f_005fclzsi2">Runtime Function: <em>int</em> <strong>__clzsi2</strong> <em>(unsigned int <var>a</var>)</em></dt>
<dt id="index-_005f_005fclzdi2">Runtime Function: <em>int</em> <strong>__clzdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>
<dt id="index-_005f_005fclzti2">Runtime Function: <em>int</em> <strong>__clzti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>
<dd><p>These functions return the number of leading 0-bits in <var>a</var>, starting
at the most significant bit position.  If <var>a</var> is zero, the result is
undefined.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fctzsi2">Runtime Function: <em>int</em> <strong>__ctzsi2</strong> <em>(unsigned int <var>a</var>)</em></dt>
<dt id="index-_005f_005fctzdi2">Runtime Function: <em>int</em> <strong>__ctzdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>
<dt id="index-_005f_005fctzti2">Runtime Function: <em>int</em> <strong>__ctzti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>
<dd><p>These functions return the number of trailing 0-bits in <var>a</var>, starting
at the least significant bit position.  If <var>a</var> is zero, the result is
undefined.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fffsdi2">Runtime Function: <em>int</em> <strong>__ffsdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>
<dt id="index-_005f_005fffsti2">Runtime Function: <em>int</em> <strong>__ffsti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>
<dd><p>These functions return the index of the least significant 1-bit in <var>a</var>,
or the value zero if <var>a</var> is zero.  The least significant bit is index
one.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fparitysi2">Runtime Function: <em>int</em> <strong>__paritysi2</strong> <em>(unsigned int <var>a</var>)</em></dt>
<dt id="index-_005f_005fparitydi2">Runtime Function: <em>int</em> <strong>__paritydi2</strong> <em>(unsigned long <var>a</var>)</em></dt>
<dt id="index-_005f_005fparityti2">Runtime Function: <em>int</em> <strong>__parityti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>
<dd><p>These functions return the value zero if the number of bits set in
<var>a</var> is even, and the value one otherwise.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fpopcountsi2">Runtime Function: <em>int</em> <strong>__popcountsi2</strong> <em>(unsigned int <var>a</var>)</em></dt>
<dt id="index-_005f_005fpopcountdi2">Runtime Function: <em>int</em> <strong>__popcountdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>
<dt id="index-_005f_005fpopcountti2">Runtime Function: <em>int</em> <strong>__popcountti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>
<dd><p>These functions return the number of bits set in <var>a</var>.
</p></dd></dl>

<dl>
<dt id="index-_005f_005fbswapsi2">Runtime Function: <em>int32_t</em> <strong>__bswapsi2</strong> <em>(int32_t <var>a</var>)</em></dt>
<dt id="index-_005f_005fbswapdi2">Runtime Function: <em>int64_t</em> <strong>__bswapdi2</strong> <em>(int64_t <var>a</var>)</em></dt>
<dd><p>These functions return the <var>a</var> byteswapped.
</p></dd></dl>

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